For many years, the stock option has been an investment device used primarily by speculators and some “sophisticated” investors. During the past few years, much more attention has been paid to options by mutual funds, insurance companies, and conservative investors who previously showed little concern for this investment alternative. The opening of the Chicago Board of Trade's exchange for the trading of options will lead to even wider interest in the area.

The trading of security options is one of the fastest growing and most dynamic areas of investment concern. When the Chicago Board of Trade's proposal to develop an exchange for trading option contracts is implemented, security option trading will become an even more important aspect of the investment world.

In so far as the concept of systematic risk is predicated on the Sharpe-Lintner theory of capital market equilibrium [5, 4], the time-horizon of systematic risk must conform with the time-horizon of market equilibrium. Since it has been suggested that market equilibrium is instantaneous [3, p. 188], it would follow that systematic risk should also be instantaneous. This paper is, therefore, concerned with the evaluation and measurement of instantaneous risk. Although Jensen [3] has made a similar attempt in a much larger study, we have reason to believe it is not satisfactory. We shall then begin in Section I by discussing Jensen's approach to the horizon problem. In Section II, an alternative procedure of evaluating systematic risk is suggested. Section III concludes the paper by comparing estimates of instantaneous risks based upon weekly returns of 30 Dow-Jones stocks. The motivation behind the paper is obvious. A correct formulation of instantaneous systematic risk is not only a logical extension of the capital market equilibrium theory but is also a yardstick for measuring portfolio performance in terms of risk and return.

The advent of the computer has permitted financial theorists to collect and analyze large amounts of financial data. In the field of investments some of the most important work has focused on historical rates of return in investments in common stocks. The classical study in this area is the Fisher-Lorie study [8, 9] in which intern al rates of return were calculated for every security listed on the New York Stock Exchange from 1926–1965. Other studies related to the area have been complicated by Herzog [10], Fisher [6, 7], Latané and Young [11], Soldofsky and Biderman [12], and Evans [3, 4].

This study examines call option values implicit in U.S. corporate bonds from 1973 to 1994. The average call option value is 2.25% of par. Over time, call values remain close to zero until one year before the first call date, reach a maximum at the beginning of the callable period, and slowly decrease thereafter. The determinants of call values are examined. The results show that bonds of firms that have called aggressively in the past have larger call values. Additionally, lower interest rates, smaller slopes of the yield curve, and higher interest rate volatility lead to larger call values. The results also show that call values increase with time to maturity in the callable period but decrease with time to maturity in the call protection period. Lower rated, higher coupon bonds have larger call values. There is no evidence that the length of the call protection period affects call values.

Recent research on blockholders focuses on activist hedge funds and documents positive stock but negative bond returns. This study investigates the role of blockholder heterogeneity on security market effects and target firm follow-on activities across three important dimensions: identity, motive, and purchasing method. We show that target firms’ security returns and post-acquisition activities strongly correlate with blockholder heterogeneity. Further, bond returns are significantly positive for firms with blockholders’ debt-assistance motive while both stock and bond returns are significantly negative in private placements. Overall, our findings highlight the importance of blockholder heterogeneity on the valuation and performance consequences in block acquisitions.